Locally brewed liquor apparently tainted with lethal chemicals has killed another 20 people in southern India, bringing the death toll from the past four days to 90, police said Tuesday.

Bootleggers began selling the deadly brew Saturday after police shut authorized liquor shops in parts of the Karnataka state because of voting for the state government, said Sri Kumar, the state police chief.

In India, liquor stores and bars are routinely closed during elections to prevent politicians from handing out free alcohol in a bid to win votes.

Since the liquor went on sale, 90 people, mostly poor laborers, have died and more than a dozen have been hospitalized, according to a police officer in Bangalore, the capital of Karnataka state. The officer spoke on condition of anonymity because he was not authorized to talk to reporters.

The officer said 56 deaths occurred in and around Bangalore, India's key information technology hub, and 21 died in neighboring Kolar district. Another 13 people died in a village just across the border with Tamil Nadu state.

On Monday, Kumar said six people had been arrested for selling the killer concoction, and police were analyzing the drink to determine what made it so deadly.

Deaths from illicitly brewed liquor are frequent in Indian villages and towns, where locally made brew is often spiked with pesticides or chemicals like the banned methyl alcohol to make it stronger or increase the amount.